U.S. patent number 6,828,503 [Application Number 10/753,944] was granted by the patent office on 2004-12-07 for terminal box device for a solar cell module and a connecting method for a terminal box device.
This patent grant is currently assigned to Sumitomo Wiring Systems, Ltd.. Invention is credited to Makoto Higashikuzono, Tadashi Sugino, Hiroyuki Yoshikawa.
United States Patent |
6,828,503 |
Yoshikawa , et al. |
December 7, 2004 |
**Please see images for:
( Certificate of Correction ) ** |
Terminal box device for a solar cell module and a connecting method
for a terminal box device
Abstract
Connecting terminals (25a to 25d) are accommodated side by side
in a terminal box casing (21). Diodes (30a to 30c) are connected
electrically between the respective connecting terminals (25a to
25d). The diodes (30a to 30c) are connected in series via the
intermediate terminal mounts (28a, 28b). Partition walls (24) for
partitioning diode accommodation spaces (23a to 23c) for at least
partly accommodating the diodes (30a to 30c) are formed in the
terminal box casing (21).
Inventors: |
Yoshikawa; Hiroyuki (Yokkaichi,
JP), Higashikuzono; Makoto (Yokkaichi, JP),
Sugino; Tadashi (Yokkaichi, JP) |
Assignee: |
Sumitomo Wiring Systems, Ltd.
(Yokkaichi, JP)
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Family
ID: |
32854094 |
Appl.
No.: |
10/753,944 |
Filed: |
January 8, 2004 |
Foreign Application Priority Data
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Jan 8, 2003 [JP] |
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2003-001943 |
Jan 21, 2003 [JP] |
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2003-012017 |
Dec 4, 2003 [JP] |
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2003-405402 |
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Current U.S.
Class: |
174/50; 174/58;
439/535; 220/4.02 |
Current CPC
Class: |
H02S
40/34 (20141201); H01R 9/2425 (20130101); H02S
40/345 (20141201); Y02E 10/50 (20130101); H01L
2924/0002 (20130101); H01L 2924/0002 (20130101); H01L
2924/00 (20130101) |
Current International
Class: |
H01L
31/048 (20060101); H02G 003/08 () |
Field of
Search: |
;174/50,58,59,60,52.1
;220/3.94,4.02,3.8 ;439/535 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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11-26035 |
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Jan 1999 |
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JP |
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2001-119058 |
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Apr 2001 |
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JP |
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2002-57360 |
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Feb 2002 |
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JP |
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2002-252356 |
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Sep 2002 |
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JP |
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Primary Examiner: Patel; Dhiru R.
Attorney, Agent or Firm: Hoopos; Gerald E. Casella; Anthony
J.
Claims
What is claimed is:
1. A terminal box device to be equipped for a solar cell module,
comprising: a terminal box casing, and a plurality of connecting
terminals arranged in the terminal box casing and connected with a
plurality of connecting elements from photoelectric conversion
elements of the solar cell module, wherein: two of the plurality of
connecting terminals are adapted to be connected with a pair of
connection cables so that the connection cables can be drawn out
from the terminal box casing, the terminal box casing comprises a
plurality of accommodating spaces for accommodating a plurality of
rectifying elements to be electrically connected between the
adjacent connecting terminals, and the respective rectifying
elements are connected in series via intermediate terminal mount(s)
in the terminal box casing.
2. The terminal box device of claim 1, further comprising at least
one partition wall partitioning the accommodating spaces for
accommodating the respective rectifying elements.
3. The terminal box device of claim 2, wherein a filler is disposed
in the terminal box casing and an air layer is inside the partition
wall.
4. The terminal box device of claim 1, wherein the connecting
terminals are arranged substantially side by side substantially at
even intervals and the intermediate terminal mount(s) are arranged
at the outer sides of the respective connecting terminals.
5. The terminal box device of claim 1, wherein a pin-shaped
connecting member is used as a connecting member between the
intermediate terminal mount and the connecting terminal to be
connected with the intermediate terminal mount.
6. The terminal box device of claim 1, wherein a non-linear
connecting member is used as a connecting member between the
intermediate terminal mount and the connecting terminal to be
connected with the intermediate terminal mount.
7. The terminal box device of claim 6, wherein a part of the
nonlinear connecting member is outside the terminal box casing.
8. A terminal box device for a solar cell module, comprising: a
terminal box casing, a plurality of rectifying element
accommodating spaces for a plurality of rectifying elements each
including a main body, a first lead terminal and a second lead
terminal having better thermal conductivity than the first lead
terminal, a plurality of terminal pairs corresponding to the number
of the rectifying elements, each terminal pair including a first
terminal to be connected with the first lead terminal and a second
terminal to be connected with the second lead terminal, and at
least one radiating intermediate terminal for connecting at least
one pair of the first and second terminals to be connected with the
adjacent rectifying elements such that the respective rectifying
elements are connected in series.
9. The terminal box device of claim 8, wherein the first lead
terminal is substantially in the form of a plate, and the second
lead terminal is made to have a better thermal conductivity than
the first lead terminal by forming the first lead terminal to have
a smaller cross-sectional area than the second lead terminal.
10. The terminal box device of claim 9, wherein the first terminal,
the second terminal and the radiating intermediate terminal are
substantially flat plates.
11. The terminal box device of claim 8, wherein the radiating
intermediate terminal is integral with at least one of the first
and second terminals for intermediate connection.
12. A method for connecting a lead terminal and a terminal in a
terminal box casings of a terminal box device for a solar cell
module, the terminal box casing having a plurality of rectifying
elements each including the lead terminal and the terminal to be
connected with the lead terminal, the method comprising: placing
the lead terminal and the terminal one over the other with a solder
therebetween and, holding a pair of electrodes in contact with the
lead terminal and the terminal, applying a current between the
electrodes to heat the solder, thereby soldering the lead terminal
and the terminal.
13. The connecting method of claim 12, wherein operation holes are
formed in portions of the terminal box casing where the lead
terminal and the terminal are to be connected, and wherein the
method further comprises bringing the pair of electrodes into
contact with the lead terminal and the terminal through the
operation holes, thereby connecting the lead terminal and the
terminal by soldering.
14. A method for connecting a lead terminal and a terminal in a
terminal box casing of a terminal box device for a solar cell
module, the terminal box casing having a plurality of rectifying
elements each including the lead terminal and the terminal to be
connected with the lead terminal, the method comprising: placing
the lead terminal and the terminal one over the other and, holding
a pair of electrodes in contact with the lead terminal and the
terminal, applying a current between the pair of electrodes to
connect the lead terminal and the terminal by resistance welding.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a terminal box device for a solar cell
module and a connecting method for such a terminal box device.
2. Description of the Related Art
A known system for generating solar energy arranges solar cell
modules in matrix on a roof of a house or the like. Terminal box
devices are provided for connecting the solar cell modules with
other solar cell modules.
Japanese Unexamined Patent Publication No. 2002-252356 discloses a
known terminal box device with built-in bypass diodes. The bypass
diodes are connected in parallel with solar cells contained in the
solar cell module and are reverse-biased with respect to the output
polarity of the respective solar cells. A current of this solar
cell is bypassed to the bypass diode if a reverse bias voltage is
applied to the solar cell.
Other technologies relating to the terminal box device for a solar
cell device are disclosed in Japanese Unexamined Patent Publication
No. 2002-57360, Japanese Unexamined Patent Publication No.
2001-119058 and Japanese Unexamined Patent Publication No.
H11-26035.
The diode in the aforementioned terminal box device generates heat
due to the current flowing therethrough. For example, the terminal
box device disclosed in Japanese Unexamined Patent Publication No.
2002-252356, has a plurality of adjacent diodes connected in series
and disposed in a single casing. This entire solar cell module
takes a negative polarity. Thus, adjacent diodes may experience a
synergistic thermal influence by each other to increase the
temperature of the diodes considerably if the currents run through
all the diodes connected in series. Diodes that reach an abnormally
high temperature in this way may, in a worst-case scenario, be
short-circuited.
Moreover, the aforementioned diode has a poor thermal conductivity
since the upper lead plate is formed with slits and a waist portion
and is relatively thin. Thus, heat developed by the
rectifying-element main body is difficult to radiate from the upper
lead plate to the outside, and a junction temperature of the
rectifying-element main body is likely to increase.
In view of the above problem, an object of the present invention is
to suppress or reduce temperature increases of rectifying
elements.
SUMMARY OF THE INVENTION
The invention relates to a terminal box device for a solar cell
module. The terminal box device comprises a terminal box casing.
Connecting terminals are arranged in the terminal box casing and
are connected with a plurality of connecting elements from
photoelectric conversion elements of the solar cell module. Two of
the connecting terminals are adapted to connect with a pair of
connection cables so that the connection cables can be drawn out
from the terminal box casing. The terminal box casing comprises
accommodating spaces for accommodating rectifying elements to be
connected electrically between the adjacent connecting terminals,
and the respective rectifying elements are to be connected in
series via intermediate terminal mounts in the terminal box casing.
Thus, heat developed in the rectifying elements becomes difficult
to transfer to the adjacent rectifying elements. Accordingly,
temperature increases of the rectifying elements due to the mutual
thermal influence of the rectifying elements are suppressed.
The terminal box device may further have at least one partition
wall partitioning the accommodating spaces for the respective
rectifying elements.
A filler preferably is filled at least partly in the terminal box
casing and/or an air layer is formed inside the partition wall.
The terminal box device may further comprise a partition wall for
partitioning the rectifying elements and a filler in the terminal
box casing. The partition wall suppresses heat transfer through the
filler, and temperature increases of the rectifying elements are
suppressed more effectively.
The terminal box device may further comprise a partition wall in
the terminal box casing for partitioning the respective rectifying
elements, and an air layer may be formed inside the partition wall.
Accordingly, heat transfer from one rectifying element to another
is suppressed by the air layer in the partition wall, and
temperature increases of the rectifying elements are suppressed
more effectively.
The connecting terminals may be arranged substantially side by side
at substantially even intervals and the intermediate terminal
mounts may be arranged at the outer sides of the respective
connecting terminals. Accordingly, a plurality of connecting
elements from the photoelectric conversion elements of the solar
cell module can be connected at substantially even intervals.
A pin-shaped connecting member may be used between the intermediate
terminal mount and the connecting terminal connected with the
intermediate terminal mount. Accordingly, heat transfer from the
rectifying element to other rectifying elements via the pin-shaped
connecting member is suppressed, and temperature increases of the
rectifying elements are suppressed more effectively.
A non-linear connecting member may be used between the intermediate
terminal mount and the connecting terminal that is connected with
the intermediate terminal mount. Accordingly, heat becomes
difficult to transfer from one rectifying element to another, and
temperature increases of the rectifying elements are suppressed
more effectively.
Part of the nonlinear connecting member may be located outside the
terminal box casing. Accordingly, heat is radiated at a portion of
the connecting member outside the terminal box casing and heat
becomes difficult to transfer from one rectifying element to
another. Thus, temperature increases of the rectifying elements are
suppressed more effectively.
The invention also relates to a terminal box device for a solar
cell module. The terminal box device comprises a terminal box
casing with a plurality of rectifying element accommodating spaces
for accommodating a plurality of rectifying elements. Each
rectifying-element has a main body, a first lead terminal and a
second lead terminal that has a better thermal conductivity than
the first lead terminal. The terminal box device also includes a
plurality of terminal pairs corresponding to the number of the
rectifying elements. Each terminal pair includes a first terminal
to be connected with the first lead terminal, a second terminal to
be connected with the second lead terminal, and at least one
radiating intermediate terminal for connecting at least one pair of
the first and second terminals to be connected with the adjacent
rectifying elements such that the respective rectifying elements
can be connected in series. Accordingly, the terminal box device
for a solar cell module has an excellent property of radiating the
heat of rectifying elements.
The invention also relates to a terminal box device for a solar
cell module where rectifying elements are provided in a terminal
box casing. Each rectifying element has a main body with first and
second electrodes. A first lead terminal is connected with the
first electrode, and a second lead terminal is connected with the
second electrode. The second lead terminal has a better thermal
conductivity than the first lead terminal. Terminal pairs are
provided and correspond to the number of the rectifying elements.
Each terminal pair has a first terminal connected with the first
lead terminal and a second terminal connected with the second lead
terminal. At least one radiating intermediate terminal for
connecting the first and second terminals is connected with the
adjacent rectifying elements such that the respective rectifying
elements are connected in series.
As described above, heat developed by the rectifying-element main
body is transferred from the second lead terminal having a
relatively higher heat radiating property to the second terminal
and then further to the first terminal connected with the adjacent
rectifying element via the radiating intermediate terminal. The
heat is radiated in these respective heat transfer paths. Thus, the
rectifying element has a good heat radiating property.
The first lead terminal may be a plate, and the second lead
terminal may be made to have a better thermal conductivity than the
first lead terminal by forming the first lead terminal with a
smaller cross-sectional area than the second lead terminal. For
example, the first lead terminal may be thinner than the second
lead terminal and/or the first lead terminal may have at least one
slit and/or the first lead terminal may have a waist portion.
Accordingly, thermal stresses on portions connecting the
rectifying-element main body and the first and second lead
terminals can be alleviated since the first lead terminal is easily
resiliently deformable.
The first terminal, the second terminal and/or the radiating
intermediate terminal may be substantially flat plates.
Accordingly, heat can be radiated efficiently from the first
terminal, the second terminal and the radiating intermediate
terminal.
The radiating intermediate terminal preferably is formed integrally
or unitarily with the first terminal and/or the second terminal for
intermediate connection. Accordingly, an assembling operability of
the terminal box device is improved and heat can be transferred
more efficiently to provide a better heat radiating property.
The invention also relates to a method for connecting a lead
terminal and a terminal in a terminal box casing of a terminal box
device. The terminal box device may be one of the above-described
terminal box devices for a solar cell module. The terminal box
device may include a terminal box casing for a plurality of
rectifying elements each including the lead terminal and the
terminal to be connected with the lead terminal. The method
preferably comprises placing the terminal and the lead terminal one
over the other with solder therebetween. The method then includes
holding a pair of electrodes in contact with the lead terminal and
the terminal and applying a current between the pair of electrodes
to heat the solder, thereby soldering the lead terminal and the
terminal. Accordingly, the solder between the lead terminal and the
terminal is heated to solder the lead terminal and the
terminal.
Alternatively, the method may employ resistance welding. Thus, the
lead terminal and the terminal are joined merely by applying a
current between the electrodes. Thus, the connecting operation is
performed in a relatively short period.
This connecting method can be applied in a case where at least one
of the first and second lead terminals is connected with the
corresponding one of the first and second terminals upon producing
the terminal box device for a solar cell module.
The method may include forming operation holes in portions of the
terminal box casing where the lead terminal and the terminal are to
be connected. The rectifying elements and the terminal may be
fixedly accommodated in the terminal box casing, and the electrodes
may be brought into contact with the lead terminal and the terminal
through the operation holes, thereby connecting the lead terminal
and the terminal by soldering and/or resistance welding.
These and other objects, features and advantages of the invention
will become more apparent upon reading of the following detailed
description of preferred embodiments and accompanying drawings. It
should be understood that even though embodiments are separately
described, single features thereof may be combined to additional
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an electrical construction of a
solar generating system.
FIG. 2 is a plan view of a terminal box device for a solar cell
module according to one embodiment of the invention.
FIG. 3 is a section along 3--3 of FIG. 2.
FIG. 4 is a plan view of a terminal box device according to a first
modification.
FIG. 5 is a plan view of a terminal box device according to a
second modification.
FIG. 6 is a schematic plan view of a terminal box device for a
solar cell module according to a second embodiment of the
invention.
FIG. 7 is a partial enlarged plan view of a bypass diode used in
the terminal box device of FIG. 6.
FIG. 8 is a section along 8--8 of FIG. 6.
FIG. 9 is a schematic plan view of a terminal box device for a
solar cell module according to a third embodiment.
FIG. 10 is a schematic plan view of a terminal box device for a
solar cell module according to a fourth embodiment.
FIG. 11 is a schematic section showing a first connecting method
for connecting a lead terminal and a terminal.
FIG. 12 is a schematic section showing another mode of the first
connecting method.
FIG. 13 is a schematic section showing a second connecting method
for connecting the lead terminal and the terminal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram showing an electric construction of the
solar generating system. This solar generating system is provided
with solar cell modules 1, terminal box devices 20 to be equipped
for the respective solar cell modules 1 and at lest one connecting
box 10. The respective solar cell modules 1 each have a plurality
of solar cells 4 electrically connected in series and arranged in a
substantially two-dimensional matrix on a roof of a house, solar
cell farm or the like to receive a natural sun light.
The terminal box device 20 is mounted, for example, on the
underside of each solar cell module 1 and connects the solar cell
module 1 with the other solar cell modules 1 and/or with the
external connecting box 10.
Bypass diodes 30a to 30c are connected in series and function as
rectifying elements in the terminal box device 20. The respective
diodes 30a to 30c are connected in parallel while being
reverse-biased with respect to the output polarity of the
respective solar cells 4 (or cell groups each comprised of a
plurality of solar cells 4). Thus, if a reverse bias voltage is
applied to a specific solar cell 4, for example, because no sun
light falls on this solar cell 4, the current running through this
solar cell 4 is bypassed to the diodes 30a to 30c.
One diode 30a to 30c is provided for each solar cell 4 (or each
cell group) in each solar cell module 1. Thus, in this embodiment,
three diodes 30a to 30c are provided for one solar cell module 1
(see FIG. 2). In FIG. 1, only one diode 30a to 30c is shown for one
solar cell module 1.
Each solar cell module 1 is connected with the other adjacent solar
cell modules 1 via connection cables 15 drawn out by way of the
terminal box device 20 mounted on the underside thereof. The solar
cell modules 1 are connected electrically in series.
Two connection cables 15 are drawn out from the solar cell module 1
and are connected with the connecting box 10, an inverter or the
like for taking electric energies out from the respective solar
cell modules 1. Thus, the electric energies are converted into an
alternate current and are taken out.
The terminal box device 20 has a terminal box casing 21, connecting
terminals 25a to 25d, the connection cables 15 and diodes 30a to
30c, as shown in FIG. 2. The terminal box casing 21 is made e.g. of
a synthetic resin and includes a box main body 21a with a
substantially rectangular casing structure that has an open end
defining an accommodating recess. A plate-shaped lid (not shown) is
mountable on the upper opening of the box main body 21a to close
the accommodating recess.
Wiring holes 22a are formed along one side (upper side in FIG. 2)
of the bottom surface of the box main body 21a, and two cable
introducing holes 22b are formed at the opposite ends of a side
wall at the other side (lower side in FIG. 2) of the box main body
21a.
Ends of lead frames 16 are drawn out from the respective solar
cells 4 or cell groups of the solar cell module 1 and are pulled
into the terminal box casing 21 through the wiring holes 22a. The
connection cables 15 are introduced through the respective cable
introducing holes 22b and connect the solar cell modules 1 or the
connection cables 15 used to transfer an electric power from the
solar cell module 1 to the outside.
Two partition walls 24 are formed in the terminal box casing 21 for
partitioning the accommodating recess into three diode
accommodating spaces 23a to 23c one after another along the
longitudinal direction LD. A single diode 30a to 30c is
accommodated in each diode accommodating space 23a to 23c. Thus,
the partition walls 24 partition the respective diodes 30a to
30c.
Each partition wall 24 is formed with a pin insertion groove 24a,
into which a jumper pin 34 is inserted.
Recessed grooves 24g are formed in parts of the partition walls 24
spaced from the pin insertion grooves 24a and extend substantially
along the surfaces of the partition walls 24. Thus, air layers are
formed in the recessed grooves 24g (see FIG. 3).
Four connecting terminals 25a to 25d are fixed side by side in the
terminal box casing 21. One end of each of the connecting terminals
25a, 25d is connected with an end of the lead frame 16 drawn out
from each solar cell 4 or cell group of the solar cell module 1,
for example, by soldering, and the other end is connected with the
connection cable 15, for example, by crimping. The connecting
terminals 25a, 25d are in the two diode accommodating spaces 23a,
23c at the opposite ends, out of the box main body 21a.
One end of each of the other two connecting terminals 25b, 25c is
connected with an end of the lead frame 16 drawn out from each
solar cell 4 or each cell group of the solar cell module 1. The
connecting terminals 25b, 25c are accommodated substantially side
by side in the intermediate diode accommodating space 23b and are
spaced apart by a specified distance.
The three diodes 30a to 30c are accommodated respectively in the
diode accommodating spaces 23a to 23c. Each diode 30a to 30c in
this embodiment has a connection lead terminal and a lead plate
mounted on the upper and lower surfaces of a chip-shaped bare chip
diode. The lead plate functions as a radiating plate. In FIG. 2,
the lead plate at one side of each diode 30a to 30c is formed with
a zigzag portion to alleviate stress that will act on a portion
connecting the bare chip diode and each lead plate due to
temperature changes or the like.
The respective diodes 30a to 30c are connected in series via
intermediate terminal mounts 28a, 28b in the terminal box casing
21. Specifically, one intermediate terminal mount 28a, 28b is fixed
in each of the diode accommodating spaces 23a, 23c at the opposite
ends. The connecting terminals 25a to 25d and a pair of
intermediate terminal mounts 28a, 28b are arranged substantially
side by side at substantially even intervals. One intermediate
terminal mount 28a in the diode accommodating space 23a is between
the connecting terminals 25a, 25b and is fixed substantially in
parallel with the connecting terminals 25a, 25b. The other
intermediate terminal mount 28b in the diode accommodating space
23c is between the connecting terminals 25c, 25d and is fixed
substantially in parallel with the connecting terminals 25c,
25d.
The diodes 30a, 30b in the diode accommodating spaces 23a, 23c at
the opposite ends of the terminal box device 20 have ends of the
lead plates at one side soldered to the connecting, terminals 25a,
25d, and have ends of the lead plates thereof at the other side
soldered to the intermediate terminal mounts 28a, 28b.
Further, the connecting terminals 25b, 25c in the intermediate
diode accommodating space 23b are connected electrically with the
respective intermediate terminal mounts 28a, 28b via the jumper
pins 34. Specifically, one end of each of the two narrow linear
jumper pins 34 is connected to the intermediate terminal mount 28a,
28b, for example, by soldering, and the other end thereof is pulled
into the middle diode accommodating space 23b through the pin
insertion groove 24a of each partition wall 24 and connected with
the connecting terminal 25b, 25c inside, for example, by
soldering.
In this way, the diodes 30a, 30c are between the connecting
terminals 25a, 25b and between the connecting terminals 25c, 25d.
The diode 30a is connected in parallel with the solar cells 4 (or
group of the solar cells 4) connected with the connecting terminals
25a, 25b, and the diode 30c is connected in parallel with the solar
cells 4 (or group of the solar cells 4) connected with the
connecting terminals 25c, 25d.
Further, in the middle diode accommodating space 23b, the lead
plate of the diode 30b at one side is connected with the connecting
terminal 25b, for example, by soldering, and the lead plate at the
other side is connected with the connecting terminal 25c, for
example, by soldering. In this way, the diode 30b is between a pair
of connecting terminals 25b, 25c. It should be noted that the diode
30b is connected in parallel with the solar cells 4 (or group of
the solar cells 4) connected with the connecting terminals 25b,
25c.
This terminal box device 20 is assembled by mounting the lid on the
opening of the terminal box casing 21 preferably with an insulating
filler such as a silicone potting agent at least partly filled in
the accommodating recess of the terminal box casing 21.
The diodes 30a to 30c of the terminal box device 20 are connected
in series by disposing the intermediate terminal mount 28a between
the diodes 30a, 30b and disposing the intermediate terminal mount
28b between the diode 30b, 30c. Accordingly, heat developed by the
specified diodes 30a, 30c is difficult to transfer to the adjacent
diodes 30a to 30c, and temperature increases of the diodes 30a to
30c is suppressed by preventing the mutual thermal influences of
the diodes 30a to 30c.
The respective diodes 30a to 30c are partitioned by the partition
walls 24. Thus, heat transfer through the filler in the terminal
box casing 21 is suppressed by the partition walls 24. Temperature
increases of the diodes 30a to 30c also are suppressed by
preventing the mutual thermal influences of the diodes 30a to 30c.
The air layers in the partition walls 24 further suppress heat
transfer.
Furthermore, the narrow linear jumper pins 34 that connect the
intermediate terminal mounts 28a, 28b and the connecting terminals
25b, 25c have a relatively small sectional area. In this respect as
well, heat transfer between the diodes 30a to 30c is suppressed and
the temperature increases of the diodes 30a to 30c is suppressed
more effectively.
A terminal box device 120 according to a first modification is
described with reference to FIG. 4. The description of the terminal
box device 120 centers on differences from the foregoing embodiment
while the same or similar elements as those of the foregoing
embodiment are not described but merely are identified by the same
reference numerals.
The terminal box device 120 is formed with four intermediate-cable
introducing holes 122c at positions on a side wall (lower side in
FIG. 4) corresponding to the intermediate terminal mounts 28a, 28b
and the connecting terminals 25b, 25c.
Further, two intermediate cables 134 that have cores covered by
insulation coatings are used instead of or in addition to the
jumper pins 34. One end of each intermediate cable 134 is connected
with the intermediate terminal mount 28a, 28b, for example, by
crimping, whereas the other end thereof is connected with the
connecting terminal 25b, 25c, for example, by crimping. A
longitudinal middle portion of each intermediate cable 134 is
exposed to the outside from the terminal box casing 21.
Specifically, the longitudinal middle portion of each intermediate
cable 134 is drawn out of the terminal box casing 21 through the
intermediate-cable introducing hole 122c and then pulled into the
terminal box casing 21 again through another intermediate-cable
introducing hole 122c. Thus, a portion of the intermediate cable
134 outside the terminal box casing 21 is bent in a nonlinear
manner.
The nonlinear intermediate cables 134 create a longer heat transfer
paths between the intermediate terminal mounts 28a, 28b and the
connecting terminals 25b, 25c in the terminal box device 120 of
this modification. Thus, heat transfer between the diodes 30a to
30c is more difficult and temperature increases of the diodes 30a
to 30c is suppressed more effectively. It should be noted that the
intermediate cables 134 are preferably as long as possible to make
the heat transfer difficult.
Further, heat is radiated more easily to the outside because the
longitudinal middle portions of the intermediate cables 134 are
outside the terminal box casing 21. Thus, heat being transferred
between the diodes 30a to 30c is radiated in an intermediate
position, and temperature increases of the diodes 30a to 30c is
suppressed more effectively.
A terminal box device 220 according to a second modification is
described with reference to FIG. 5. The description of the terminal
box device 220 centers on differences from the foregoing embodiment
while the same elements as those of the foregoing embodiment are
not described and merely identified by the same reference
numerals.
The positions of the connecting terminals 25a, 25d and those of the
intermediate terminal mounts 28a, 28b are switched in the diode
accommodating spaces 23a, 23b at the opposite ends of the terminal
box device 220. Thus, the intermediate terminal mounts 28a, 28b are
at the outer sides of the connecting terminals. 25a, 25d.
Accordingly, the physical orientations of the diodes 30a, 30c are
reversed (direction of electrical connection or circuitry is same),
and the connecting terminals 25a, 25d and the intermediate terminal
mounts 28a, 28b are connected using relatively long jumper pins 234
to cross over the connecting terminals 25a, 25d.
Accordingly, the respective connecting terminals 25a to 25d are
arranged substantially side by side at substantially even
intervals. As a result, the lead frames 16 from the solar cells 4
(or groups of the solar cells 4) of the solar cell module can be
arranged at substantially even intervals.
A terminal box device for a solar cell module according to a second
embodiment of the invention is identified by the numeral 20 in
FIGS. 6 to 8. The terminal box device 20 is provided with a
terminal box casing 21, three diodes 30a to 30c as rectifying
elements, three terminal pairs, each of which includes one first
terminal 25a to 25c and one second terminal 26a to 26c, and two
radiating intermediate terminals 40a, 40b. Hatched portions in FIG.
6 are areas where a heat radiating effect is relatively high.
The terminal box casing 21 is made e.g. of a synthetic resin and
includes a box main body 21a that has a substantially rectangular
casing structure with an open end that defines an accommodating
recess. A substantially plate-shaped lid (not shown) can be mounted
on the opening of the box main body 21a to close the accommodating
recess.
Wiring holes 22a are formed along one side (upper side in FIG. 6)
of the bottom surface of the box main body 21a, and two cable
introducing holes 22b are formed at substantially opposite ends of
a side wall at the other side (lower side in FIG. 6) of the box
main body 21a.
Ends of lead frames 16 are drawn out from the respective solar
cells 4 (or the cell groups each comprised of a plurality of solar
cells 4) of the solar cell module 1 and are pulled into the
terminal box casing 21 through the wiring holes 22a. The connection
cables 15 that connect the solar cell modules 1 or the connection
cables 15 that transfer electric power from the solar cell module 1
to the outside are introduced through the respective cable
introducing holes 22b and are pulled into the terminal box casing
21.
Two partition walls 24 are formed in the terminal box casing 21 for
partitioning the accommodating recess into three diode
accommodating spaces 23a to 23c one after another along the
longitudinal direction LD. A single diode 30a to 30c is
accommodated in each diode accommodating space 23a to 23c.
Radiating-intermediate-terminal insertion grooves 24a' are formed
in the respective partition walls 24, and the radiating
intermediate terminals 40a, 40b are inserted through the
radiating-intermediate-terminal insertion grooves 24a' to extend
between the adjacent diode accommodating spaces 23a to 23c. The
radiating intermediate terminals 40a, 40b are exposed to allow an
effective heat radiation or dissipation.
As shown in FIGS. 6 to 8, the diodes 30a to 30c include
rectifying-element main bodies 31a to 31c, first lead terminals 32a
to 32c to be connected electrically with anode electrodes 31aa of
the rectifying-element main bodies 31a to 31c, and second lead
terminals 33a to 33c to be connected electrically with cathode
electrodes 31ab of the rectifying-element main bodies 31a to
31c.
Specifically, the rectifying-element main body 31a is formed by
placing the cathode electrode 31ab, an n-type area 31ac, a p-type
area 31ad and the anode electrode 31aa substantially one over
another in this order and is in the form of a chip having a
substantially square plan view.
The second lead terminal 33a is a plate having a substantially
rectangular plan view. The rectifying-element main body 31a is
arranged on the upper surface of one side of the second lead
terminal 33a, and the cathode electrode 31ab of the
rectifying-element main body 31a is to be connected electrically
with the second lead terminal 33a, for example, by soldering.
The first lead terminal 32a includes a substantially rectangular
lead-plate main body 32aa, and an element connecting portion 32ab
with a substantially rectangular plan view substantially equal or
similar to that of the rectifying-element main body 31ab in size.
The rectifying-element main body 31a is arranged on the lower
surface of the element connecting portion 32ab, and the anode
electrode 31aa of the rectifying-element main body 31a is to be
connected electrically with the element connecting portion 32ab,
for example, by soldering. The first and second lead terminals 32a,
33a extend from the rectifying-element main body 31a in
substantially opposite directions.
The first lead terminal 32a is made more easily resiliently
deformable than the second lead terminal 33a. For example, the
lead-plate main body 32aa and the element connecting portion 32ab
may be coupled via a waist or thinned portion 32ac that has a
reduced cross-sectional area. Thus, the first lead terminal 32a is
easily resiliently deformable at the waist portion 32ac.
Additionally or alternatively, the first lead terminal 32a may be
thinner than the second lead terminal 33a. Thus, the entire first
lead terminal 32a can flexibly and easily undergo a resilient
deformation. Furthermore, slits 34' may extend from opposite sides
in directions substantially normal to longitudinal direction LD in
a portion of the lead-plate main body 32aa near the element main
body 32ab. Thus, the first lead terminal 32a is made easily
resiliently deformable at its portion where the one or more slits
34' are formed.
Thermal stress may be exerted on the diode 30a due to a change in
ambient environment or heat developed by the rectifying-element
main body 31a itself. However, stress on portions connecting the
rectifying-element main body 31a and the respective lead terminals
32a, 33a can be taken up by making the first lead terminal 32a
easily resiliently deformable. Thus, the connecting portions of the
rectifying-element main body 31a and the respective lead terminals
32a, 33a will not peel off to cut off an electrical connection.
The first lead terminal 32a has the waist or thinned portion 32ac
and the slits 34' or is thinned to easily undergo a resilient
deformation. Thus, the sectional area of the first lead terminal
32a is made relatively smaller and has a lower thermal conductivity
than the second lead terminal 33a.
The easily deformable first lead terminal 32 is connected with the
anode electrode 31aa and the more rigid second lead terminal 33a is
connected with the cathode electrode 31ab in this embodiment.
However, a reverse arrangement may be taken.
It should be noted that the diodes 30b, 30c preferably have the
same construction as the diode 30a.
One terminal pair is provided in each of the diode accommodating
spaces 23a to 23c of the terminal box casing 21.
The first and second terminals 25a, 26a are fixed substantially
side by side at a specified spacing in the diode accommodating
space 23a at one side of the terminal box casing 21; the first and
second terminals 25b, 26b are fixed substantially side by side at a
specified spacing in the middle diode accommodating space 23b; and
the first and second terminals 25c, 26c are fixed substantially
side by side at a specified spacing in the diode accommodating
space 23c at the other side of the terminal box casing 21. The
positions of the first and second terminals 25b, 26b in the middle
diode accommodating space 23b are reversed from those in the diode
accommodating spaces 23a, 23c at the opposite sides. The respective
first and second terminals 25a to 25c, 26a to 26c are fixed to the
bottom of the terminal box casing 21 by fixing means using a known
locking construction.
Each of the first and second terminals 25a to 25c, 26a to 26c is
made of a conductive metallic into a substantially flat plate
having a substantially rectangular plan view. In the respective
diode accommodating spaces 23a to 23c, the first lead terminals 32a
to 32c of the respective diodes 30a to 30c are connected
electrically with the first terminals 25a to 25c, for example, by
soldering, and the second lead terminals 33a to 33c thereof are
connected electrically with the second terminals 26a to 26c, for
example, by soldering.
One end of the first terminal 25a in the diode accommodating space
23a at one side, one end of each of the first and second terminals
25b, 26b in the middle diode accommodating space 23b, and one end
of the second terminal 26c in the diode accommodating space 23c at
the other side are connected with ends of the lead frames 16 drawn
out from the respective solar cells 4 or cell groups of the solar
cell module 1. Further, the other end of the first terminal 25a in
the diode accommodating space 23a at one side and the other end of
the second terminal 26c in the diode accommodating space 23c at the
other side are connected with the external connection cables 15,
for example, by crimping.
The radiating intermediate terminals 40a, 40b connect the first
terminals 25a to 25c and the second terminals 26a to 26c to be
connected with the adjacent diodes 30a to 30c so that the
respective diodes 30a to 30c are connected in series. Specifically,
each of the radiating intermediate terminals 40a, 40b is made of a
conductive metallic into a substantially plate-shaped member having
a substantially L- or U-shaped plan view. In this embodiment, the
radiating intermediate terminals 40a, 40b are strips having
substantially the same width as the first and second terminals 25a
to 25c, 26a to 26c.
One end of the radiating intermediate terminal 40a at one side is
connected with the second terminal 26a in the diode accommodating
space 23a while the other end thereof is pulled into the middle
diode accommodating space 23b through the
radiating-intermediate-terminal insertion groove 24a' of the
partition wall 24 and connected with the first terminal 25b
therein. Further, one end of the radiating intermediate terminal
40b at the other side is connected with the first terminal 25c in
the diode accommodating space 23c while the other end thereof is
pulled into the middle diode accommodating space 23b through the
radiating-intermediate-terminal insertion groove 24a' of the other
partition wall 24 and connected with the second terminal 26b
therein.
In this way, the respective diodes 30a to 30c are connected in
series via the first terminals 25a to 25c, the second terminals 26a
to 26c and the radiating intermediate terminals 40a, 40b.
The respective ends of the radiating intermediate terminals 40a,
40b and the first and second terminals 25a to 25c, 26a to 26c are
connected to be easily electrically and thermally conductive. In
this embodiment, the respective ends of the radiating intermediate
terminals 40a, 40b and the first and second terminals 25a to 25c,
26a to 26c are fastened to the bottom of the terminal box casing 21
by fastening means such as screws while being placed one
substantially over the other to establish a connection.
Heat developed by the diode 30a is transferred from the second lead
terminal 33a having a relatively higher thermal conductivity to the
second terminal 26a, then further to the first terminal 25b
connected with the adjacent diode 30b via the radiating
intermediate terminal 40a. The heat is radiated in these elements,
particularly in the adjacent first terminal 25b. Thus, the diode
30a and connected elements have a good heat radiating property,
thereby preventing an increase of the junction temperature of the
diode 30a.
The connection cable 15 is connected with the first terminal 25a
connected with the diode 30a. Thus, the heat of the first terminal
25a radiates to the outside via the connection cable 15 and,
therefore, the first terminal 25a has a relatively good heat
radiating property. Accordingly, a temperature difference between
the diode 30a and the first terminal 25a becomes larger as the
temperature of the diode 30a increases. Thus, heat is relatively
easily transferred from the diode 30a to the first terminal 25a. In
this respect as well, the temperature of the diode 30a is prevented
from increasing.
Heat developed by the diode 30b is transferred from the second lead
terminal 33b having a relatively higher thermal conductivity to the
second terminal 26b, then further to the first terminal 25c
connected with the adjacent diode 30c via the radiating
intermediate terminal 40b. The heat is radiated in these elements,
particularly in the adjacent first terminal 25c. Thus, the diode
30b and its connected elements have a good heat radiating property,
thereby preventing an increase of the junction temperature of the
diode 30b.
Heat developed by the diode 30c is transferred from the second lead
terminal 33c having a relatively higher thermal conductivity to the
second terminal 26c. The connection cable 15 is connected with the
second terminal 26c. Thus, the heat radiates to the outside and is
dissipated via the connection cable 15. Accordingly, the second
terminal 26c has a higher heat radiating property than the other
second terminals 26a, 26b. The transferred heat is radiated to the
outside via the connection cable 15. Therefore the diode 30c and
its connected elements have a good heat radiating property and an
increase in the junction temperature of the diode 30c is
prevented.
The first terminals 25a to 25c, the second terminals 26a to 26c and
the radiating intermediate terminals 40a, 40b are substantially
flat plates in this embodiment. Thus, heat is radiated efficiently
in the respective elements.
The terminal box device has the three diodes 30a to 30c in the
foregoing embodiment. However, the invention also is applicable to
a terminal box device with two, four or more diodes.
A terminal box device for a solar cell module according to a third
embodiment of the invention is described with reference to FIG. 9.
It should be noted that the same or similar elements as those of
the terminal box device described in the second embodiment are not
described in this embodiment but merely are identified by the same
reference numerals.
The terminal box device of FIG. 9 has integrated radiating
terminals 140a and 140b. The integrated radiating terminal 140a is
an integral unit of the second terminal 26a, the first terminal 25b
and the radiating intermediate terminal 40a of the second
embodiment. The integrated radiating terminal 140b is an integral
unit of the second terminal 26b, the first terminal 25c and the
radiating intermediate terminal 40b of the second embodiment. These
integrated radiating terminals 140a, 140b each are formed, for
example, by stamping, cutting or forming one conductive metallic
plate. The integrated radiating terminals 140a, 140b are exposed to
the outside towards the opening of the terminal box casing 21 so
that heat can be radiated effectively therefrom.
The terminal box device has the integrated radiating terminals
140a, 140b integral or unitary to the second terminals 26a, 26b,
the first terminals 25b, 25c and the radiating intermediate
terminals 40a, 40b. Thus, the number of steps of mounting these
parts into the terminal box device is reduced. Further, the heat
radiation from the diodes 30a to 30c is sufficient.
A terminal box device for a solar cell module according to a fourth
embodiment of the invention is described with reference to FIGS. 10
to 13. It should be noted that the similar or same elements as
those of the terminal box device described in the second and third
embodiments are not described in this embodiment but are identified
by the same reference numerals.
In the second and third embodiments, the first lead terminals 32a
to 32c and the second lead terminals 33a to 33c are connected
electrically with the first terminals 25a to 25c and the second
terminals 26a to 26c, for example, by soldering. The first and
second lead terminals 32a to 32c, 33a to 33c are constructed to
have an improved heat radiating property by letting heat escape to
the radiating intermediate terminals 40a, 40b as described above.
Thus, a soldering operation using a soldering iron has a poor
operability. For instance, a period of 20 seconds or longer is
required for the soldering operation. In this way, a need to
improve the heat radiating effect from the diodes 30a to 30c and a
need to improve the soldering operation conflict with each
other.
Accordingly, a method is provided for connecting the first lead
terminals 32a to 32c and the second lead terminals 33a to 33c of
the respective diodes 30a to 30c with the first terminals 25b, 25c
and the second terminals 26a, 26b of the integrated or unitary
radiating terminals 140a, 140b, the other first terminal 25a and
second terminal 25c (see round hatched portions in FIG. 10). The
connecting method described here is similarly applicable to a case
where the first terminals 25a to 25c and the second terminals 26a
to 26c, which are elements separate from the radiating intermediate
terminals 40a, 40b, are to be connected with the corresponding lead
terminals 32a to 32c, 33a to 33c of the respective diodes 30a to
30c as in the second embodiment.
According to this first connecting method, as shown in FIG. 11 or
12, one of the first and second terminals 25b, 25c, 26a, 26b of the
integrated radiating terminals 140a, 140b and the first and second
terminals 25a, 26c (hereinafter, this terminal is merely referred
to as a terminal 225 in this embodiment) is accommodated in the
body main body 21a of the terminal box casing 21, and a suitable
amount of cream solder S is applied to a surface of an end of this
terminal 225. An end of the corresponding one of the first lead
terminals 32a to 32c and the second lead terminals 33a to 33c
(hereinafter, this lead terminal is merely referred to as a lead
terminal 232 in this embodiment) is placed on the surface of the
end of the terminal 225 to fixedly accommodate the lead terminal
232 (diode 30a to 30c) in the box main body 21a of the terminal box
casing 21. In this way, the terminal 225 and the lead terminal 232
are placed one substantially over the other with a solder present
therebetween.
Then, the electrodes 250a, 250b are brought into contact with the
terminal 225 and the lead terminal 232 placed one substantially
over the other. In one mode, the electrodes 250a, 250b arranged at
the opposite sides of the terminal 225 and the lead terminal 232
are brought into contact with the terminal 225 and the lead
terminal 232 to press them from opposite sides as shown in FIG. 11.
In another mode, the pair of electrodes 250a, 250b are arranged
close to each other while defining a suitable spacing therebetween,
and the terminal 225 and the lead terminal 232 placed one
substantially over the other are pressed from opposite sides by the
pair of electrodes 250a, 250b at one side and a pressing jig 252 at
the other side as shown in FIG. 12.
Operation holes 221 are formed in portions of the box main body 21a
where the terminal 225 and the lead terminal 232 are to be
connected. The electrodes 250a, 250b and the like are brought into
contact with the terminal 225 and the lead terminal 232 through the
operation holes 221.
Subsequently, pressure is applied to the pair of electrodes 250a,
250b to press the terminal 225 and the lead terminal 232. A
specified large current is applied between the electrodes 250a,
250b, thereby locally increasing the temperatures of the terminal
225, the lead terminal 232 and the solder S between them within a
short period. A current is applied either in a downward direction
or in upward direction. In this way, the cream solder S is melted
to solder the terminal 225 and the lead terminal 232.
A second connecting method joins the terminal 225 and the lead
terminal 232 by resistance-welding. Specifically, as shown in FIG.
13, the terminal 225 is accommodated in the box main body 21a and
an end of the lead terminal 232 is placed on an end of the terminal
225, thereby fixing the lead terminal 232 in the box main body 21a.
In this way, the terminal 225 and the lead terminal 232 are placed
one substantially over the other.
Electrodes 260a, 260b for resistance welding then are brought into
contact with the terminal 225 and the lead terminal 232 placed one
substantially over the other from opposite sides. Similar to the
first connecting method, operation holes 221h may be formed in
portions of the box main body 21a where the terminal 225 and the
lead terminal 232 are to be connected.
Pressure is applied to the electrodes 260a, 260b to press the
terminal 225 and the lead terminal 232 from substantially opposite
sides, and a specified large current is applied between them. Thus,
the terminal 225 and the lead terminal 232 are melted and joined by
developed heat (Joule heat). It should be noted that a current may
be applied either down or up.
At this time, the terminal 225 may have a protuberance 225a
projecting toward the lead terminal 232 to concentrate the current.
Alternatively or additionally the lead terminal 232 may be formed
with a protuberance.
According to the above connecting methods, the lead terminal 232
and the terminal 225 are soldered by applying a current between the
electrodes 250a, 250b to heat the cream solder S between the lead
terminal 232 and the terminal 225. Alternatively, the lead terminal
232 and the terminal 225 are joined by resistance welding by
applying a current between the electrodes 260a, 260b for resistance
welding. Thus, the connecting operation can be performed within a
relatively short period of, e.g. about 5 seconds.
Further, the connecting operation can be mechanized to be more
efficiently performed.
* * * * *